1. Technical Field
A cleaning solution is disclosed for removing photoresist resins remaining on underlying layer patterns formed by photolithography process using the photoresist patterns as etching mask.
2. Description of the Related Art
Conventional cleaning solutions to remove photoresist remaining on the top portion of an underlying layer are generally organic solvent including amine (—NH2) compounds.
However, conventional cleaning solutions for removing photoresist are environmentally harmful because they include excessive amounts of amine compounds and rely upon organic solvents. Conventional cleaning solutions also have a problem in that they are expensive.
Mixed solutions of H2O2/H2SO4/H2O have been also used as conventional cleaning solutions for removing photoresists. However, there is a problem in that the mixed solution erodes metal, and therefore, an underlying layer pattern is deformed when the underlying layer is metal.
FIG. 1 is a SEM photograph of a formed aluminum pattern after cleaning the remaining photoresist on the aluminum pattern using a conventional mixed cleaning solution of H2O2/H2SO4/H2O. As shown in FIG. 1, the lateral surface of the A1 pattern is severely damaged when the photoresist remaining on the A1 pattern is cleaned with the mixed solution of H2O2/H2SO4/H2O.
FIG. 2 is a SEM photograph of a formed tungsten pattern after cleaning the remaining photoresist on the tungsten pattern using a conventional mixed cleaning solution of H2O2/H2SO4/H2O. As shown in FIG. 2, the lateral surface of the W pattern is severely damaged when the photoresist remaining on the W pattern is cleaned with the mixed solution of H2O2/H2SO4/H2O.